Özet:
Coking wastewater contains high a concentration of refractory
and toxic compounds to be treated before being discharged
into the environment. The water quality usually
cannot meet the discharge limits after conventional biological
treatment processes. This article initially investigated the
treatability of coking wastewater with conventional and
modified Fenton processes for advanced treatment of coking
wastewater. Based on the experimental results, up to 86% of
chemical oxygen demand (COD) and 99.5% of phenol
removals were achieved by the conventional Fenton process
at original pH 7.8 within 60 min. pH adjustment was not
performed due to the sudden drop in the original pH value,
after the addition of Fenton’s reagents. A modified Fenton
process yielded comparable COD (82%) and phenol (98.5%)
removals within 120 min at pH 3.0. The optimal operating
conditions were determined as [Fe21] 5 300 mg/L, [H2O2] 5
4000 mg/L, and pH 5 7.8 for a conventional Fenton process,
and [Fe0] 5 300 mg/L, [H2O2] 5 4500 mg/L, and pH 5 3 for
a modified Fenton process. 2011 American Institute of Chemical
Engineers Environ Prog, 32: 176–180, 2013